Hybrid vehicles typically include a transmission controller that computes a target torque based on the difference between a number of target input rotations and a number of actual input rotations during and after shifting of the transmission. Then, torque to be produced at the transmission is calculated based on lever ratio and inertia of each element, and torque to be output for driving is calculated based on a demanded driving force and lever balance at a variable speed mode. The torque to be produced at the transmission is combined with the torque to be output for driving, thereby setting a torque command value. As for each torque generating element, e.g., an engine or an electric motor, the transmission controller controls the lever by outputting the predetermined torque command value to shift at the appropriate speed.
In conventional systems, the transmission control device of a hybrid vehicle calculates torque for transmission, the inertia of each torque generating element (e.g., an engine, a first motor and a second motor) is offset by the torque generating elements themselves so that the gear is shifted. Therefore, for example, when the gear is shifted to a low transmission gear ratio by a “kick-down” operation, the driving force cannot exceed the one which is determined by combination of the torque for driving each of the torque generating elements. Thus, it is typically not possible to expect an increase of a driving force in response to the kick-down operation of the driver.